KOKOTO WebChat (Fabric, Forge)

## KOKOTO WebChat 5.1.0

5.1.0 is a feature, reliability, compatibility, and security update over the **5.0.0** public release baseline.

Server Relay Version Compatibility

Server-to-server relay in KWC 5.1.0 is not backward-compatible with older KWC versions. All servers connected through relay must be updated to the same KWC version before they are connected.

Mixed-version relay configurations are not supported and may cause duplicate messages, incorrect server metadata, or malfunction of features such as DMs, replies, and emojis.

⚠️ Important: Server relay does not support connections between different KWC versions. Update all participating servers to the same version.

### Security — Relay Protocol v2

**Who should prioritize this upgrade:** servers that enabled/configured Relay v1 in KWC 5.0.0 or a compatible BMWC relay deployment. Servers that did not use server relay are not affected by the relay-specific issue.

- Relay v1 over `http://` carried relay payloads without transport encryption, so those deployments are the highest-priority upgrade case.
- Relay v1 also used a flat peer trust set and top-level shared secret. HTTPS protected the network hop, but exposure of that secret or a peer/forwarding misconfiguration still affected the whole flat relay trust set.
- Relay v2 replaces that model with explicit `groups -> peers`, one shared secret per group, reciprocal same-group peer configuration, request-by-request authenticated encryption, replay/loop defenses, and authenticated responses.
- Relay v2 payloads use directional HKDF-SHA256 keys and AES-256-GCM. Protection is hop-by-hop, not end-to-end; forwarding servers remain trusted participants.
- Direct one-hop HTTP remains possible with an explicit warning because the v2 payload itself is encrypted/authenticated, but HTTP peers cannot be forwarding hops. Forwarding is same-group HTTPS only.
- Legacy Relay v1/BMWC endpoints return HTTP 426.
- The first **5.0.0 -> 5.1.0** migration disables relay instead of guessing new trust groups. Reconfigure reciprocal v2 groups before re-enabling it.

### Cross-server chat, DM, and Reply

- Public relay, cross-server DM delivery/read receipts, stable remote identities, duplicate protection, and forwarding now use the same Relay v2 trust boundary.
- Added persistent Web/game DM and group-chat Reply metadata, original-message preview/jump, restart persistence, and server-side validation.
- Unified game-side private Reply presentation with public Reply while preserving private delivery scope.
- Fixed `/kchat group` room names containing spaces/quotes/repeated whitespace and added optional real membership join/leave notices.
- Improved narrow/mobile DM/group metadata layout.

### Emoji, notifications, pins, and browser UI

- Canonicalized custom emoji names/tokens, improved Reply URL/emoji rendering, exact-token picker insertion, and emoji catalog recovery after fetch/SSE/catalog changes.
- Custom emoji now render in the notification center and pinned-message UI with compact size limits without changing normal chat emoji sizing.
- Fixed refresh-time history emoji that could stay blank until the message scrolled out of view and back; transient custom-emoji image failures are retried in place.
- Fixed exact account chat-profile persistence/application, including intentionally unset visual fields.
- Avoided Android Chrome Autofill accessory UI on normal chat composers and switched administrator emoji upload to the generic system file picker path.

### HTTP, SSE, configuration, and operations

- Raised default SSE limits to **10 per resolved client IP / 500 total** with clearer 429/trusted-proxy diagnostics.
- Added EN/KO/JA/ZH config comment templates selected by `ui.language` and a complete **394-setting** administrator input guide.
- Migration/difference output now compares semantic YAML paths/values and preserves readable structured YAML.
- Fixed Relay config reconstruction for multiple groups/peers.
- Added localized warnings for externally exposed plain-HTTP listeners and direct HTTP Relay peers.
- Repeated operational HTTP/network failures now suppress identical repeats, summarize them, and report recovery while still logging the first/changed failure immediately.
- Web-command execution notices can also be delivered to online Minecraft players when enabled.
- Update checks use `kokoto-webchat` first and fall back to `bluemapwebchat` during the project-address transition.

### Compatibility

- Fixed Fabric 1.18.2 legacy mixin packaging/startup.
- Fixed NeoForge 1.21.1 modern metadata startup (`InvalidModFileException: Missing ModLoader`).
- Fixed Forge 1.18.2–1.19.4 runtime dependency packaging.
- Fixed Forge/NeoForge runtime Minecraft target reporting so exact-target JARs no longer report a hard-coded `26.2` value.
- Bukkit/Paper/Spigot: Minecraft 1.18–26.2
- Fabric: 16 exact targets, Minecraft 1.18.2–26.2
- NeoForge: 12 exact targets, Minecraft 1.20.2–26.2
- Forge: 16 exact targets, Minecraft 1.18.2–26.2
- Mod-loader targets use Java 17/21/25 according to Minecraft version; Bukkit uses Java 17.

### Documentation and source packages

- Reorganized and synchronized the English/Korean/Japanese/Simplified-Chinese documentation and Wiki.
- Consolidated duplicate/version-specific upgrade/reference pages and canonicalized Wiki diagrams.
- Public source packages contain product/build source only; internal validation scripts/harnesses are distributed separately as validation tools.